Nozzle for a floor cleaning device

ABSTRACT

A nozzle for a floor care appliance for cleaning surfaces. The nozzle includes a gliding sole disposed on a bottom side of the floor nozzle and has a suction mouth opening. A suction duct extends from the opening to a connection piece. A front suction mouth edge and a rear suction mouth edge bound the suction mouth with respect to a pushing direction of the floor nozzle. A rear pivot limit stop associated with the rear suction mouth edge and a front pivot limit stop associated with the rear suction mouth edge are included. The rear suction mouth edge projects beyond a plane of contact of the nozzle with the surface when the rear suction mouth edge engages the front pivot limit stop and when the floor nozzle is in a non-contacting position. The front pivot limit stop limits the pivoting angle of the rear suction mouth edge in a direction toward the front suction mouth edge such that the rear suction mouth edge is in a substantially vertical position with respect to the plane of contact when the rear suction mouth edge engages the front pivot limit stop.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2008/003413, filed on Apr. 28, 2008, and claims benefit to German Patent Application No. DE 10 2007 022 256.6, filed on May 9, 2007. The International Application was published in German on Nov. 20, 2008 as WO 2008/138477 A2 under PCT Article 21 (2).

FIELD

The present invention relates to a nozzle for a floor care appliance used for cleaning surfaces such as textile floor coverings and smooth floors

BACKGROUND

DE 199 00 557 A1 and DE 298 03 415 U1 describe a floor nozzle including a gliding sole that is arranged on the bottom side inside and which an opening is provided in the form of a suction mouth.

DE-OS 2 139 157 describes a floor nozzle with a pressure lip made of metal or plastic that is disposed within the effective range of the suction mouth, said pressure lip being pivotable between a forward inclined position and a rearward inclined position.

In canister vacuum cleaners, stick vacuum cleaners, and upright vacuum cleaners, floor nozzles are connected to a suction wand via the connection piece and are continuously alternately pushed and pulled across a floor surface to clean the same. Generally, the floor nozzles are provided with a ring of bristles which can be extended for cleaning smooth floor surfaces and within which the dirt then accumulates and is sucked away. During carpet cleaning, the ring of bristles is retracted and therefore not active. During this vacuuming operation, the carpet pile is raised in the direction of movement by the suction mouth edges provided on the gliding sole. This allows the vacuum air flow to penetrate between the individual pile fibers, enabling the floor nozzle to also pick up the dust that adheres at the bottom of the pile.

When pulling the floor nozzle backwards on high-pile carpets, the floor nozzle is slightly lifted at its rear portion. This reduces the mechanical action exerted by the rear suction mouth edge on the carpet pile, so that a smaller amount dust is removed from the carpet. During forward movement, the rear suction mouth edge is slightly pressed into the carpet and, therefore, increases the resistance to movement.

European Patent EP 1 320 317 B1 describes providing the sole plate with a pivoting mechanism that is used to lower the front suction mouth edge during forward movement and the rear suction mouth edge during backward movement. The air path from the suction mouth via the suction duct to the connection piece must be well sealed to avoid suction losses, which, in the case of a movable sole plate, is difficult to achieve and involves a high level of complexity.

German document DE 199 00 557 A1 describes forming the rear suction mouth edge as a thin-walled, elastically deformable rib. This reduces the resistance during forward movement of the floor nozzle. When moving the floor nozzle backward, the tip of the lip is exactly in the plane of contact of the floor nozzle, which is defined by the front suction mouth edge and a wheel attached to the nozzle in the rear portion thereof.

In the floor nozzle described in DE 298 03 415 U1, the front and rear suction mouth edges are each formed by a pivoting plow blade. The end regions of the plow blades do project beyond what is referred to as transverse gliding edges, but during both forward and backward movement, they are located above the plane of contact of the floor nozzle, which here is defined by front support rollers and rear support wheels.

SUMMARY

In view of the above, an aspect of the present invention is to provide a floor nozzle in such a way that it ensures satisfactory cleaning results even on high-pile carpets and provides great ease of use, and yet is relatively simple to construct.

In an embodiment, the present invention provides a nozzle for a floor care appliance for cleaning surfaces. The nozzle includes a gliding sole disposed on a bottom side of the floor nozzle and has a suction mouth opening. A suction duct extends from the opening to a connection piece. A front suction mouth edge and a rear suction mouth edge bound the suction mouth with respect to a pushing direction of the floor nozzle. A rear pivot limit stop associated with the rear suction mouth edge and a front pivot limit stop associated with the rear suction mouth edge are included. The rear suction mouth edge projects beyond a plane of contact of the nozzle with the surface when the rear suction mouth edge engages the front pivot limit stop and when the floor nozzle is in a non-contacting position. The front pivot limit stop limits the pivoting angle of the rear suction mouth edge in a direction toward the front suction mouth edge such that the rear suction mouth edge is in a substantially vertical position with respect to the plane of contact when the rear suction mouth edge engages the front pivot limit stop.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention is explained in more detail below and schematically shown in the drawing, in which:

The FIGURE is a cross section of a floor nozzle in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

In an embodiment, the present invention relates to a nozzle for a floor care appliance used for cleaning surfaces such as textile floor coverings and smooth floors, said nozzle having a gliding sole which is arranged on the bottom side and inside which an opening is provided in the form of a suction mouth. A suction duct extends from the opening to a connection piece. The suction mouth is bounded by suction mouth edges with respect to the pushing direction of the floor nozzle. The rear suction mouth edge is pivotable about an axis that extends transverse to the pushing direction and the rear suction mouth edge is associated with a rear pivot limit stop and front pivot limit stop.

One aspect of the present invention is that resistance to movement encountered during forward movement of the floor nozzle is reduced and, secondly, that the mechanical action exerted on a carpet during backward movement of the floor nozzle is increased. This is achieved because the rear suction mouth edge projects beyond the plane of contact of the floor nozzle when it engages the front pivot limit stop and the floor nozzle is in a non-contacting position. This allows deeper penetration into the carpet during backward movement. During forward movement, the rear suction mouth edge pivots out of this active position. Forward movement should not be hindered by the front pivot limit stop. Therefore, the front pivot limit stop should be set back from the plane of contact of the floor nozzle.

In an embodiment, restoring forces act on the rear suction mouth edge in a direction toward the front suction mouth edge. This provides close contact with the surface to be cleaned, and thus high suction power, during forward movement. Most simply, the rear suction mouth edge is formed by the lower edge of a flexible lip. It is advantageous if the flexibility of the lip in the region of the pivot axis is greater than in the region of contact with the surface to be cleaned. In this manner, the lip is prevented from bending away during backward movement of the nozzle, ensuring that sufficient bending forces are applied to the pile.

To assist in the sealing action during forward movement, it the rear suction mouth edge may be associated with a rear pivot limit stop. This prevents this edge from bending back into a region in which it would no longer actively seal the suction mouth. The rear pivot limit stop may limit the pivoting angle of the rear suction mouth edge in a direction toward the connection piece in such a way that it is between 45° and 90°, and preferably about 70°, starting from a position perpendicular to the plane of contact of the floor nozzle.

To assist in the mechanical action on the carpet, the rear suction mouth edge may be associated with a front pivot limit stop. This substantially prevents bending in a direction toward the front suction mouth edge during backward movement of the nozzle, which in turn would result in poorer contact with the carpet. Conveniently, the front pivot limit stop limits the pivoting angle of the rear suction mouth edge in a direction toward the front suction mouth edge in such a way that when the rear suction mouth edge engages the front pivot limit stop, it is in an at least nearly vertical position with respect to the plane of contact.

The FIGURE shows a cross-section through a nozzle 1 which is designed in accordance with the present invention and which in conjunction with, for example, a canister or stick vacuum cleaner is suitable for cleaning textile floor coverings and smooth floors. The nozzle includes a plastic housing 2 which merges into a pivotally mounted connection piece 3. Wheels 4 are arranged below connection piece 3 for increased maneuverability and ease of movement of nozzle 1. A gliding sole 5 is inserted in housing 2, said gliding sole being generally made of plastic material or deep-drawn from sheet metal. A height-adjustable peripheral ring of bristles 7 is arranged between the edge of gliding sole 5 and housing side walls 6. The adjustment mechanism is not relevant to the present invention and will therefore not be further described. Gliding sole 5 is provided with a square opening known as suction mouth 8. A suction duct 9 extends from suction mouth 8 to connection piece 3.

Suction mouth 8 is formed by a front suction mouth edge 81 and a rear suction mouth edge 82. In order to clean a surface in need of treatment, floor nozzle 1 is pushed forward and pulled backward in the directions symbolized by double-headed arrow 10 in the FIGURE. In the process, front suction mouth edge 81 and the lowest points 41 of the wheels make contact, defining a plane of contact symbolized by line 11.

Front suction mouth edge 81 is formed from gliding sole 5, while rear suction mouth edge 82 is formed by the lower edge of a flexible lip 83, the latter being secured in a corresponding receptacle 51 in gliding sole 5. Lip 83 is formed using a dual injection molding process, the portion 84 which is in contact with the floor covering being made from a hard material. The material portion 85 in the region of receptacle 51 is of greater flexibility. Because of this, lip 83; i.e., rear suction mouth edge 82, is pivotable about an axis that extends transverse to the pushing direction, as symbolized by double-headed arrow 86. The flexibility in the region of the pivot axis results in a restoring force in the direction of front suction mouth edge 81. A resilient hinge may be used in place of flexible portion 85 to secure lip 83; i.e., rear suction mouth edge 82. Such an embodiment is not shown in the drawing. When nozzle 1 is not in contact with the floor, lower edge 82 of the lip projects a distance D between 0.5 mm and 4 mm beyond the plane of contact, which is shown in the enlarged view of detail A.

The space behind lip 83 is configured to act as a rear pivot limit stop 87 for rear suction mouth edge 82. The inclination of gliding sole 5 in this region allows lip 83; i.e., rear suction mouth edge 82, to pivot through an angle of from about 45° to 90°, preferably of about 70°, relative to the normal (to the plane of contact). A rigid web 88 is disposed in front of rear suction mouth edge 82, said web being set back from the plane of contact by a distance d between 0.5 mm and 4 mm. Web 88 forms a front pivot limit stop, so that the resiliently returned lip 83 remains in a nearly vertical position (with respect to the plane of contact).

Unlike with a conventional floor nozzle, rear flexible suction mouth edge 82 no longer increases the push force during forward movement of floor nozzle 1. Due to the contact with the carpet pile, lip 83 pivots backward and is moved at a flat adapted angle across the floor covering. This also ensures a good seal of suction duct 9 against the surface being cleaned, regardless of the height of the pile.

During backward movement of floor nozzle 1, rear suction mouth edge 82 is important for efficient pick-up of dust. In conventional floor nozzles 1, rear suction mouth edge 82 would no longer comb through the carpet pile so effectively because of the above-described slight lifting of the rear portion of floor nozzle 1. Since the flexible suction mouth edge 82 described herein is altogether longer, and because it bears against the front limit stop (web 88) in a position perpendicular to the floor covering, the contact with the carpet pile is much more aggressive than with conventional floor nozzles. This results in an increased dust pick-up efficiency. Because of the contact with the floor occurring during the use of nozzle 1, lip 83 is indeed slightly bent in a direction toward front suction mouth edge 81, but it is nevertheless ensured that lip 83 penetrates deeper into the pile than front suction mouth edge 81. This ensures that even a short pile will be raised.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing form the spirit and scope of the invention. 

1-7. (canceled)
 8. A nozzle for a floor care appliance for cleaning a surface, the nozzle comprising: a gliding sole disposed on a bottom side of the floor nozzle, the gliding sole having a suction mouth opening; a suction duct extending from the opening to a connection piece; a front suction mouth edge and a rear suction mouth edge, each bounding the suction mouth opening with respect to a pushing direction of the floor nozzle; a rear pivot limit stop associated with the rear suction mouth edge; and a front pivot limit stop associated with the rear suction mouth edge, wherein the rear suction mouth edge projects beyond a plane of contact of the nozzle with the surface when the rear suction mouth edge engages the front pivot limit stop and the floor nozzle is in a non-contacting position, and wherein the front pivot limit stop limits the pivoting angle of the rear suction mouth edge in a direction toward the front suction mouth edge such that the rear suction mouth edge is in a substantially vertical position with respect to the plane of contact when the rear suction mouth edge engages the front pivot limit stop.
 9. The floor nozzle as recited in claim 8, wherein the rear suction mouth edge is configured such that restoring forces act on the rear suction mouth edge in a direction toward the front suction mouth edge
 10. The floor nozzle as recited in claim 8, wherein the rear suction mouth edge is a lower edge of a flexible lip.
 11. The floor nozzle as recited in claim 9, wherein the rear suction mouth edge is a lower edge of a flexible lip.
 12. The floor nozzle as recited in claim 10, wherein a flexibility of the lip is greater in a region of a pivot axis than in a region of contact with the surface.
 13. The floor nozzle as recited in claim 11, wherein a flexibility of the lip is greater in a region of a pivot axis than in a region of contact with the surface.
 14. The floor nozzle as recited in claim 8 wherein the rear pivot limit stop limits a pivoting angle of the rear suction mouth edge in a direction toward the connection piece to between 45° and 90° with respect to a position perpendicular to the plane of contact of the floor nozzle.
 15. The floor nozzle as recited in claim 14 wherein the rear pivot limit stop limits the pivoting angle of the rear suction mouth edge to about 70° with respect to the position perpendicular to the plane of contact of the floor nozzle.
 16. The floor nozzle as recited in claim 9 wherein the rear pivot limit stop limits a pivoting angle of the rear suction mouth edge in a direction toward the connection piece to between 45° and 90° with respect to a position perpendicular to the plane of contact of the floor nozzle.
 17. The floor nozzle as recited in claim 10 wherein the rear pivot limit stop limits a pivoting angle of the rear suction mouth edge in a direction toward the connection piece to between 45° and 90° with respect to a position perpendicular to the plane of contact of the floor nozzle.
 18. The floor nozzle as recited in claim 12 wherein the rear pivot limit stop limits a pivoting angle of the rear suction mouth edge in a direction toward the connection piece to between 45° and 90° with respect to a position perpendicular to the plane of contact of the floor nozzle.
 19. The floor nozzle as recited in claim 8 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle.
 20. The floor nozzle as recited in claim 9 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle.
 21. The floor nozzle as recited in claim 10 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle.
 22. The floor nozzle as recited in claim 12 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle.
 23. The floor nozzle as recited in claim 14 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle.
 24. The floor nozzle as recited in claim 15 wherein the front pivot limit stop is disposed at a distance from the plane of contact of the floor nozzle. 